Research Paper Volume 8, Issue 7 pp 1540—1570

Figure 6. Cyclin A2 is involved in both homologous recombination and non-homologous end joining. (A) Schematic of experiments in (C) and (D). (B) Silencing of CCNA2 by siRNA was confirmed by western blot. (C) siRNA silencing of CCNA2 reduces HR. U251 cells with an integrated pDR-GFP plasmid were transfected with pCBASceI to induce a DSB in the DR-GFP locus. Cells that repaired this DSB by HR express GFP. Percentage CCNA2-silenced cells expressing GFP were normalized to percentage of control cells expressing GFP. Unpaired t-test, * = p < 0.05, n=3 independent experiments. (D) Silencing of CCNA2 reduces NHEJ. Experiments were performed as in (C), but with an integrated EJ5GFP plasmid. Unpaired t-test, * = p < 0.05, n=4 independent experiments. The y-axes in (C) and (D) are the percentage of GFP-positive cells in each condition normalized to the control siRNA condition transfected with pCBASceI plasmid. Error bars represent SEM for all graphs. (E) Lentiviral silencing CCNA2 sensitizes cells to IR by clonogenic assay. CCNA2-silenced cells demonstrate reduced survival compared to control cells with scrambled shRNA. The x-axis is dose, and the y-axis is surviving fraction. Unpaired t-test at each dose, * = p < 0.05, n=3 independent experiments. Error bars for all graphs represent s.e.m.